Metro screen door system is a typical mechatronics product. It is arranged along the edge of the platform to separate the station platform from the driving tunnel area and reduce the operation energy consumption of the station air conditioning and ventilation system. At the same time, the impact of train operation noise and piston wind on the station is reduced, accidents caused by personnel falling off the track are prevented, a comfortable and safe waiting environment is provided for passengers, and the service level of the subway is improved.

PSD control system is mainly composed of central interface panel (PSC), local control panel (PSL), door control unit (DCU), communication medium, communication interface and peripheral equipment. The central interface panel (PSC) is also composed of main monitoring system (MMS), two unit controllers (pedc), wiring terminals, interface equipment and control distribution circuit. A typical station is equipped with one central interface panel (PSC), two local control panels (PSL) and one door control unit (DCU) for each sliding door.

2. System function and Realization

(1) Control function

The control system has system level control (SIG), platform level control (PSL), manual operation control and fire mode (IBP). Among them, manual operation control has high priority and low system level. Low level operations can be performed only after priority operations are performed.

(2) System level control (SIG)

System level control refers to the way in which the signal system (SIG) directly controls the PSD under normal operation mode. Under the system level control mode, when the train arrives at the station and stops within the allowable error range (e.g. ± 300mm), the signal system sends the command of "long / short train opening / closing" to the unit controller (pedc) on each side of PSD. The unit controller (pedc) controls each sliding door in real time through the door control unit (DCU), so as to realize the system level control operation of PSD. The unit controller (pedc) is connected with the door control unit (DCU) through reliable hard wire.

(3) Platform level control (PSL)

Platform level control refers to the control mode of "opening / closing" PSD by train driver or station attendant on the local control panel (PSL) of the platform. When the system level control cannot be realized normally, the train driver or station attendant can "open / close" the PSD through "special key" and "open / close button" on the local control panel (PSL), so as to realize the platform level control operation of PSD.

(4) Manual operation control

Manual operation refers to the operation of PSD by platform personnel or passengers. When the power supply of the control system fails or the operating mechanism of individual PSD fails, the platform staff can use the "special key" at the platform side or the passenger can open the PSD through the "door handle" at the track side. And upload relevant status information.

(5) Fire mode control (IBP)

In case of fire in tunnel / station, in order to cooperate with the station environmental control system to execute the fire mode, the PSD system must be controlled, and the station staff shall conduct emergency operation on the PSD system through the button on the emergency backup panel (IBP) in the station integrated control room. All connections are hard wired.

(6) Monitoring function

The main monitoring system (MMS) is the core part of the central interface panel (PSC) and completes the integration of relevant information of PSD units on each side. It completes the following functions through the monitoring unit controller (pedc), door control unit (DCU), power supply system and communication with the main control system (MCS) and system maintenance terminal (SMT):

a. Collect all DCU information through internal PSD network;

b. Provide maintenance data;

c. It is allowed to modify DCU parameters;

d. Allow to download new DCU software;

e. Send PSD data to MCS through optical fiber;

f. PSD fault alarm storage, PSD normal system operation record;

g. The self diagnosis data of DCU is transmitted to MMS;

h. MMS is stored in hard disk. The storage capacity meets the information storage requirements;

i. Print data;

j. MMS can store the fault diagnosis information of DCU;

k. MMS downloads GPS clock from MCS.

(7) Unit controller (pedc)

The monitoring signal between the unit controller (pedc) and the main monitoring system (MMS) is realized through reliable hard wire connection. Each unit controller (pedc) will provide its operation status (logic level signal) to the logic input module of the main monitoring system (MMS). The main monitoring system (MMS) monitors the basic operation status of PSD system, such as "open long / short door" and "close door" command signals from signal system (SIG), "PSL operation permission" signal from platform local control panel (PSL), "interlock release" signal from platform local control panel (PSL), "open long / short door" command and "close door" command from local control panel (PSL) From the "door opening" command and "door closing" command signal started on IBP panel, "all ASD / eed closed and locked" signal, etc.

(8) Door control unit (DCU)

The monitoring between door control unit (DCU) and main monitoring system (MMS) is realized by using communication network (Fieldbus). Each door control unit (DCU) has an address on the network. In engineering, in order to facilitate management and identification, the address of each door control unit (DCU) can depend on the position of the door control unit (DCU) on the platform (up / down line, door unit number). The main monitoring system (MMS) monitors the relevant status information of the door control unit (DCU).